YouTube user Juan del Real was at a skate park in Alameda, an island on the opposite side of the bay to San Francisco proper. There, on a runway at the now closed naval air station, del Real spotted a camouflaged Tesla Model X undergoing testing.
Tesla's Fremont factory, formerly a joint venture plant between GM and Toyota, is located about 50 kilometres to the south. That facility reportedly has a test track of its own; it's not entirely clear why the company needed or wanted to test the Model X within the limited confines of the disused naval base.
Filmed on his iPhone with the digital zoom set to maximum, it's clear that the production version of the Model X shares the same basic proportions as the concept car, which was unveiled back in 2012. The side window shapes seem to have changed slightly since then, though.
Pitched as a cross between an SUV and a people mover, the Model X concept premiered with one particularly eye-catching feature, aside from its all-electric drivetrain: rear falcon-wing doors.
Since the concept car's unveiling, the Model X has been delayed multiple times, with Elon Musk, Tesla's CEO, confirming in November last year that the Model X is now on track for a debut in the third quarter of 2015. The company's website indicates that new orders won't be delivered until early 2016.